The overall goal of this SBIR Phase I proposal is to establish the measurement reliability and the clinical feasibility of the RGR-GAIT instrumented gait analysis system. Gait dysfunction can dramatically affect a person's ability to perform activities of daily living, and assessment of gait is a critical component of physical therapy practice. Currently, instrumented gait analysis is inaccessible to the vast majority of physical therapy clinics. Because of this, most clinicians depend on observational gait analysis, which has been shown to have inadequate reliability and validity. Further, two-dimensional gait analysis does not capture many critical three- dimensional (3-D) gait features. Clinical outcomes could be improved if three-dimensional gait deviations could be more objectively quantified in a typical clinic, but current 3-D systems are too space intensive, costly, and technically demanding. The Retro-Grate Reflector (RGR) 3-D motion capture system is a novel single-camera 3-D motion tracking technology that fills the gap between clinical need and currently available 3-D systems. Through innovation in the use of moire patterns generated by a lightweight, multi-layer passive optical target, the RGR technology is able to determine 3-D information with a single camera. The RGR system's single camera operation, automatic tracking of multiple targets and robustness to lighting conditions make it less technically demanding and overcomes the barriers for broad clinical use of instrumented gait analysis. Metria Innovation is developing the RGR-GAIT system for clinical deployment. The two aims of this proposal are to establish the inter-trial, inter-session, and inter-tester repeatability and to demonstrate the clinical feasibility of the RGR-GAIT system. A system will be constructed and deployed to a physical therapy clinic where the testing will take place. For the first aim, two therapists will collect 3-D gait data on ten healthy subjects across two days. In addition, ten orthopedic patients will be assessed by two therapists on a single day. These reliability data will inform aim 2, which will objectively quantify gait deviations in the ten orthopedic patients. The results of this study will lead to Phase II, which will focus on establishing measurement reliability between clinical sites and within clinical populations. Phase II will also refine the technology, software, and technical support for full commercialization. PUBLIC HEALTH RELEVANCE: Assessment of walking is a critical component of rehabilitation for a variety of orthopedic, neurological, and cardiopulmonary conditions. Improved assessment of walking and other movement in the clinical setting can dramatically improve patient outcomes and reduce costs by improving treatment planning. The result of this project will be an innovative gait analysis system to meet this need.